And that's how I found myself leaning over my laptop, forgetting about lunch altogether as my mind gorged itself on new ideas. The article was titled The Genius Neuroscientist Who Might Hold the Key to True AI by Shaun Raviv. The byline made a bold claim: "Karl Friston's free energy principle might be the most all-encompassing idea since Charles Darwin's theory of natural selection. But to understand it, you need to peer inside the mind of Friston himself."
The piece began by discussing Friston's typical day as the scientific director of the University College London's Functional Imaging Laboratory (FIL) and establishing his credibility as an influential and serious neuroscientist.
When Friston was inducted into the Royal Society of Fellows in 2006, the academy described his impact on studies of the brain as “revolutionary” and said that more than 90 percent of papers published in brain imaging used his methods. Two years ago, the Allen Institute for Artificial Intelligence, a research outfit led by AI pioneer Oren Etzioni, calculated that Friston is the world’s most frequently cited neuroscientist. He has an h-index — a metric used to measure the impact of a researcher’s publications — nearly twice the size of Albert Einstein’s. Last year Clarivate Analytics, which over more than two decades has successfully predicted 46 Nobel Prize winners in the sciences, ranked Friston among the three most likely winners in the physiology or medicine category.
Wired
A journalist's voice popped into my head, reciting a Ron Burgundy quote in the third person: "Do you know who Friston is? I don't know how to put this, but he's kinda a big deal. People know him. He's very important. He has many leather-bound books, and his apartment smells of rich mahogany."
I chuckled to myself. This Friston guy sounds like he's making an impact on the world. Good on him.
I continued reading.
For the past decade or so, Friston has devoted much of his time and effort to developing an idea he calls the free energy principle. (Friston refers to his neuroimaging research as a day job, the way a jazz musician might refer to his shift at the local public library.) With this idea, Friston believes he has identified nothing less than the organizing principle of all life, and all intelligence as well. “If you are alive,” he sets out to answer, “what sorts of behaviors must you show?”
Wired
If it's the organizing principle of intelligence and life, then it's the organizing principle of everything, my brain casually commented. The entire universe is a conscious system. Duh.
Oh wait, I paused. I guess that's not obvious to a lot of people.
Peter Thiel's famous contrarian question echoed in my mind: "What important truth do very few people agree with you on?"
I recalled a passage from Thiel's book, Zero to One.
This question sounds easy because it’s straightforward. Actually, it’s very hard to answer. It’s intellectually difficult because the knowledge that everyone is taught in school is by definition agreed upon. And it’s psychologically difficult because anyone trying to answer must say something she knows to be unpopular. Brilliant thinking is rare, but courage is in even shorter supply than genius.
Most commonly I hear answers like the following:
“Our education system is broken and urgently needs to be fixed.”
“America is exceptional.”
“There is no God.”
Those are bad answers. The first and the second statements might be true, but many people already agree with them. The third statement simply takes one side in a familiar debate. A good answer takes the following form: “Most people believe in x, but the truth is the opposite of x.”
Peter Thiel with Blake Masters
Okay then, I thought. Most people believe the observer and the observed are separate variables. But the truth is, they're the same thing. Most people believe that the universe is primarily made from unconscious, inanimate matter. But the truth is, the entire universe is a conscious system. Most people believe life is random and chaotic. But the truth is, we're all getting a physical experience of our own consciousness. Most people believe they are thinking. But the truth is, they are merely rearranging their prejudices. Need I go on?
I continued reading the Wired article.
Friston traces his path to the free energy principle back to a hot summer day when he was 8 years old. He and his family were living in the walled English city of Chester, near Liverpool, and his mother had told him to go play in the garden. He turned over an old log and spotted several wood lice—small bugs with armadillo-shaped exoskeletons—moving about, he initially assumed, in a frantic search for shelter and darkness. After staring at them for half an hour, he deduced that they were not actually seeking the shade. “That was an illusion,” Friston says. “A fantasy that I brought to the table.”
He realized that the movement of the wood lice had no larger purpose, at least not in the sense that a human has a purpose when getting in a car to run an errand. The creatures’ movement was random; they simply moved faster in the warmth of the sun.
Friston calls this his first scientific insight, a moment when “all these contrived, anthropomorphized explanations of purpose and survival and the like all seemed to just peel away,” he says. “And the thing you were observing just was. In the sense that it could be no other way.”
Wired
And the thing you were observing just was. In the sense that it could be no other way. That sentence struck my consciousness at a strange angle, like being hit in the funny bone. It felt odd. Familiar, maybe? I couldn't put my finger on it.
I re-read it again. And the thing you were observing just was. In the sense that it could be no other way.
In the sense that it could be no other way.
In the sense that it could be no other way.
In the sense that it could be no other way.
Very strange.
I kept reading.
When Friston was in his mid-teens, he had another wood-lice moment. He had just come up to his bedroom from watching TV and noticed the cherry trees in bloom outside the window. He suddenly became possessed by a thought that has never let go of him since. “There must be a way of understanding everything by starting from nothing,” he thought. “If I’m only allowed to start off with one point in the entire universe, can I derive everything else I need from that?” He stayed there on his bed for hours, making his first attempt. “I failed completely, obviously,” he says.
Wired
I liked the way Friston's mind worked. Most people believe that problem solving is all about finding the right answer. It's not. The answer is the easy part. Formulating the right question takes most of the time and effort. The question is the focuser. If you ask a terrible question, you'll get a terrible answer — like the number forty-two, or a belief in materialism.
If I'm only allowed to start off with one point in the entire universe, can I derive everything else I need from that? Now that was the ultimate question; the ultimate focuser. I stashed it away in my mind for future use and continued reading.
Over time, Hinton convinced Friston that the best way to think of the brain was as a Bayesian probability machine. The idea, which goes back to the 19th century and the work of Hermann von Helmholtz, is that brains compute and perceive in a probabilistic manner, constantly making predictions and adjusting beliefs based on what the senses contribute. According to the most popular modern Bayesian account, the brain is an “inference engine” that seeks to minimize “prediction error.”
Wired
Cool, I thought. Makes sense.
I continued reading until a particular passage caught my attention.
Markov is the eponym of a concept called a Markov blanket, which in machine learning is essentially a shield that separates one set of variables from others in a layered, hierarchical system. The psychologist Christopher Frith — who has an h-index on par with Friston’s — once described a Markov blanket as “a cognitive version of a cell membrane, shielding states inside the blanket from states outside.”
In Friston’s mind, the universe is made up of Markov blankets inside of Markov blankets. Each of us has a Markov blanket that keeps us apart from what is not us. And within us are blankets separating organs, which contain blankets separating cells, which contain blankets separating their organelles. The blankets define how biological things exist over time and behave distinctly from one another. Without them, we’re just hot gas dissipating into the ether.
Ever since I first read about Markov blankets, I’d seen them everywhere. Markov blankets around a leaf and a tree and a mosquito. In London, I saw them around the postdocs at the FIL, around the black-clad protesters at an antifascist rally, and around the people living in boats in the canals. Invisible cloaks around everyone, and underneath each one a different living system that minimizes its own free energy.
The concept of free energy itself comes from physics, which means it’s difficult to explain precisely without wading into mathematical formulas. In a sense that’s what makes it powerful: It isn’t a merely rhetorical concept. It’s a measurable quantity that can be modeled, using much the same math that Friston has used to interpret brain images to such world-changing effect. But if you translate the concept from math into English, here’s roughly what you get: Free energy is the difference between the states you expect to be in and the states your sensors tell you that you are in. Or, to put it another way, when you are minimizing free energy, you are minimizing surprise.
According to Friston, any biological system that resists a tendency to disorder and dissolution will adhere to the free energy principle — whether it’s a protozoan or a pro basketball team.
A single-celled organism has the same imperative to reduce surprise that a brain does.
Wired
Wait. What?!
My eyes squinted at the screen.
Did he just say what I thought he said?
I scrolled down, furiously reading the remainder of the article.
This isn’t enough for Friston, who uses the term “active inference” to describe the way organisms minimize surprise while moving about the world. When the brain makes a prediction that isn’t immediately borne out by what the senses relay back, Friston believes, it can minimize free energy in one of two ways: It can revise its prediction—absorb the surprise, concede the error, update its model of the world—or it can act to make the prediction true. If I infer that I am touching my nose with my left index finger, but my proprioceptors tell me my arm is hanging at my side, I can minimize my brain’s raging prediction-error signals by raising that arm up and pressing a digit to the middle of my face.
And in fact, this is how the free energy principle accounts for everything we do: perception, action, planning, problem solving. When I get into the car to run an errand, I am minimizing free energy by confirming my hypothesis—my fantasy—through action.
For Friston, folding action and movement into the equation is immensely important. Even perception itself, he says, is “enslaved by action”: To gather information, the eye darts, the diaphragm draws air into the nose, the fingers generate friction against a surface. And all of this fine motor movement exists on a continuum with bigger plans, explorations, and actions.
“We sample the world,” Friston writes, “to ensure our predictions become a self-fulfilling prophecy.”
Wired
I blinked a few times and cocked my head to the side.
I'd already begun running the computation in my mind. It played in my head like a multi-dimensional movie, full of purple Markov blankets and yellow shaded areas that represented distributions of mutual surprise (or, as Friston called it, free energy) in the system.
I replaced the purple Markov blankets with images of the things they represented: objects, buildings, people, money. Then I did something strange. I placed Steve Jobs in the system — a man renowned for his 'reality distortion field.' I watched as Jobs' Markov blanket — his consciousness — began expressing a belief in something that didn't exist yet. As Jobs held steady to his vision, a substantial buildup of yellow 'free energy' began accumulating in the system. Jobs was deliberately creating and holding a prediction error — a gap between what the information coming into his senses told him was true, and what he believed to be true. His prediction error was throwing the entire system out of homeostasis and causing everything to rearrange to minimize the free energy.
As he spoke and convinced others of his vision, they began believing it too. Their new prediction errors generated even more free energy in the system, throwing it further into chaos. Resources were shifting around, minimizing their mutual surprise via the path of least resistance. To the naked eye, it looked like disordered mayhem.
But then the free energy began to disappear from the system. The gap between what Steve Jobs saw in his mind — what he believed to be true — and what was physically showing up in the outside world, had closed. There was no gap. He was holding a beautiful, ordered iPhone in his hands, just like he envisioned.
Holy. Fuck.
